Beauvais Cathedral (French: Cathédrale Saint-Pierre de Beauvais) is an incomplete cathedral located in Beauvais, in northern France.

It is, in some respects, the most daring achievement of Gothic architecture.

Work was begun in 1225 under count-bishop Miles de Nanteuil, the choir was completed in 1272. The vaulting in the interior of the choir reaches 48 m in height, far surpassing the concurrently constructed Cathedral of Notre-Dame in Amiens, with its 42-m nave.

The work was interrupted in 1284 by the collapse of some of the vaulting of the recently completed choir. However, large-scale Gothic design continued, and the choir was rebuilt at the same height, albeit with more columns in the chevet. The transept was built from 1500 to 1548. In 1573, the fall of a too-ambitious 153-m central tower stopped work again, after which little addition was made. This would have made the church the second highest structure in the world at the time (after St. Olaf's church, Tallinn).

In 1284, only twelve years after completion, part of the choir vault collapsed, along with a few flying buttresses. It is now believed that the collapse was caused by resonant vibrations caused by high winds. As the floor plan shows, the original design included a nave that was never built. Thus, the absence of the shouldering support of the nave contributes to the structural weakness of the cathedral.

The north transept now has four large wood and steel lateral trusses at different heights, installed during the 1990s to keep the transept from collapsing (see photograph). These temporary measures will be in place until more permanent solutions can be determined. Various studies are underway to determine with more assurance what can be done to preserve this magnificent structure. In addition, the main floor of the transept is interrupted by a much larger brace that rises out of the floor at a 45-degree angle.

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